TN75 - other tractor's 4WD engaging issue

[yeehaw]

Have a TN75 4wd w/loader 2003 model 'bout a 1000 hours- The 4wd is manually engaged, not push button, by raising a lever on the left hand side. up 4wd - down 2wd....What I have started to notice is that it will engage fine into 4wd, although I kinda have to find the "right" place for it - no just pulling up and going. The front tires spin good and all- and will take a strain (say pushing/digging dirt)-- yet after some period of time (minutes?) it will disengage on it's own even though the handle is all the way up. I can lower the handle - up again and 4wd is good again. I can even just pull up a little without lowering the handle (even though it is all the way up) and it will engage but it wont stay engaged.
(i thought the handle was just being hindered by something and needed to be able to be pulled higher, yet at the bottom it has a "c" or "u" that rocks back and forth and there is a stopper in the middle---and it is resting on the stopper when it is pulled all the way up)

I have taken a look at a schematic and it looks like there is a half moon "key" at the end of the push lever that should be locking into the gear(s) that may be worn down. Before I start ordering parts/taking on this by myself/(buddy )....
has anyone else experienced this issue as well and what was the outcome (the fix/how hard to fix...)
thanks again

 

[Robert_in_NY]

I think I recall having this issue on mine about 5 years ago. All I did was lubricated the linkages and such and worked it and everything worked fine again and still does.

 

[yeehaw]

yeah - i tried that as well as i was a little stiff in the beginning.. a little kroil on the outer components fixed the movements up and down... yet it is like it needs to go up another inch or two -but the stopper keeps it from going up anymore....(even gone under the tractor and pushed the lever up to engage the 4wd several times to see if that had any different effects--- to no avail)